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Saturday, November 3, 2018

“Breakthrough” Fuel Cell Could Advance Widespread Use of Fuel Cells

"Breakthrough" might be a loaded word to use when describing alternative energy sources, which always seem to be just beyond reach, but Machine Design uses it to describe a new type of fuel cell from Georgia Tech.  There, a team of researchers under Principal investigator Meilin Liu developed a new fuel cell that runs on methane at temperatures comparable to automobile engines. The key to developing this fuel cell was the discovery of new catalyst.
The catalyst does away with [high-]priced hydrogen fuel by making its own out of cheap, readily available methane. And improvements throughout the cell dramatically cooled the operating temperatures customary in methane fuel cells. Methane fuel cells usually require temperatures of 750 to 1,000°C. The Georgia Tech fuel cell needs only about 500°C—a notch cooler than automobile combustion engines, which run at around 600°C.

That lower temperature could trigger cascading cost savings in the ancillary technologies needed to operate a fuel cell, potentially pushing the new cell to commercial viability. The researchers express confidence that engineers can design electric power units around this fuel cell, something that has eluded previous methane fuel cells.
Fuel cells and the circus of trying to put them in cars (which have never been sold at a profit) are not new topics around this blog.  I'm always trying to keep an eye open for new technologies that might change the dynamics of the field and turn the "$100k car they can sell for $40k" into something more practical. As I said a while back:
I'm not suggesting that nobody works on these things, that's how big breakthroughs happen, I'm just suggesting the odds for that aren't very good and that those R&D projects should not get funded out of tax money. 
This new catalyst fuel cell could be the real thing.  The transition from laboratory to production is famously difficult and a lot of ideas die along the way.  Back to Machine Design for the gritty details:
The research was based on a type of fuel cell with high potential for commercial viability, the solid oxide fuel cell (SOFC). SOFCs are known for their versatility in using different fuels. If the new fuel cell goes to market, it still might not power automobiles for a while. Instead it could first land in basements as part of a more decentralized, cleaner, cheaper electrical power grid. The fuel cell would be about the size of a shoebox, not counting the other equipment needed to make it run.
Cascading innovations, including a brand new one, let researchers reimagine the fuel cell, making it run on methane at lower temperatures. The ruthenium-nickel based catalyst, here in green, was the latest materials innovation in the new fuel cell. (Credit: Georgia Tech/Liu lab)

“The hope is you could install this device like a tankless water heater,” Liu says. “It would run off of natural gas to power your house…That would save society and industry the enormous cost of new power plants and large electrical grid expansions.

“It would also make homes and businesses more power independent,” he adds. “That kind of system would be called distributed generation, and our sponsors want to develop that.”

Hydrogen is the best fuel for powering fuel cells, but its cost is exorbitant. Researchers figured out how to convert methane to hydrogen in the fuel cell itself via the new catalyst, which is made with cerium, nickel, and ruthenium and has the chemical formula Ce0.9Ni0.05Ru0.05O2 (abbreviated CNR).

When methane, water molecules, and heat contact the catalyst, nickel chemically cleaves the methane molecule. Ruthenium does the same with water. The resulting parts come back together as hydrogen (H2) and carbon monoxide (CO), which researchers put to good use. Although CO causes performance problems in most fuel cells, in this one they can use it as a fuel.

H2 and CO move on to other catalyst layers that make up the anode, the part of the fuel cell that pulls off electrons, making the carbon monoxide and hydrogen positively charged ions. The electrons travel via a wire creating the electricity flow toward the cathode.

There, oxygen sucks up the electrons, closing the electrical circuit and becoming O2 ions. Ionized hydrogen and oxygen meet and exit the fuel cell as water condensation; the carbon monoxide and oxygen ions meet to become pure carbon dioxide, which could be captured.
The ability to create its needed hydrogen out of methane is very strong advantage for this fuel cell.  Among the drawbacks of current fuel cell-based cars are the high pressure hydrogen tanks involved; one source said the Toyota fuel cell vehicle is using 11 lb tanks at 10,000 PSI.  Assume that about half the hydrogen is replaced with air, and you get a nice explosive mixture with an energy of around 300 Mega Joules (MJ) - equivalent to about 300 sticks of dynamite or nearly nearly 80 lbs of TNT.  Fuel tanks over 11,000 MJ are being planned for trucks.

This fuel cell looks to be able to eliminate the hydrogen tank.  Whether it can be "safe" or not is going to involve a lot of engineering.  I always assume that anything capable of producing or storing energy is potentially unsafe, from the gallon gas can for the lawnmower to the starting battery in a car, to smaller batteries, too. 


16 comments:

  1. Looks like the breakthrough is the new catalyst. SOFC's have been around for quite a while. "CQ VHF" had an article about the one they used for Field Day probably 10 years ago. It was about the size of my little Honda EU2000i generator, and you screwed a tank of propane, like a torch cylinder, into it, and pure, sweet DC power came out, to do with as you please.

    Unfortunately I don't remember the fuel consumption or how much DC it put out. They ran one, entire HF station from it, they liked it, but cautioned that it got REALLY hot.

    This could mitigate that one big problem.

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  2. The viability of this could rest on this new catalyst. It is said to require
    Ruthenium....which is pretty damn rare, and most sources currently available are NOT in the USA.

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  3. Ruthenium is hovering around 265 USD per troy oz. Ratchet up the demand and what happens?

    http://www.infomine.com/investment/ruthenium/

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    Replies
    1. Yeah but platinum is $867/oz and palladium is $1105/oz and both of those are used in your car's catalytic converter. In neither your car or this fuel cell does the rare metal get used in a pure lump form.

      In the mining industry, it's not uncommon to find that production will start and stop in an area depending on the spot price. As price goes up, areas "less profitable" to mine open up.


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  4. Where is methane so cheap and readily available that when you refill your tank you can also pick up a soda and a bag of chips? They should be trying to store the hydrogen by combining it with eight carbons, not just one.

    It would run off of natural gas to power your house...That would save society and industry the enormous cost of new power plants and large electrical grid expansions.

    To be replaced with the enormous cost of new power plants in every basement, and large natural gas pipe size expansions.

    carbon dioxide, which could be captured

    After the hydrogen is used to spin four prayer wheels for Gaia, the waste carbon could be sequestered underground by renims so it doesn't become plant food. I hear there are geologically compatible sequester sites in Pennsylvania.

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    1. What do you think is a primary source of energy to produce them electrons which currently make your monitor glow, Anonymous?

      NATURAL GAS.

      The existing pipelines already have the capability to support this country's electrical energy needs, including what growth the producers can credibly see. If you doubt it, go ask Tanker at MostlyCajun.com

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    2. You're talking about existing pipelines which run to large electrical generating plants. Those are big enough. I'm talking about existing pipelines which run to individual houses. Those are not sized to run the whole house.

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  5. I believe that fuel cells have some potential. However the only way any of the new technologies will become practical and viable is if it can be cheap, dependable and as good or better than existing technology. Otherwise it requires huge tax payer funded subsidies which are awarded to cronies of politicians. In other words if it cannot stand on it's own merits and actually be preferable to the consumer than the current technology is we are wasting our time with it.

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  6. The REAL question for this, as well as for any "magic" energy sourse, is what is its efficiency?

    Internal combustion engines can get to roughly 40% efficiency. The rest of the fuel they use gets converted to waste heat:
    https://physics.stackexchange.com/questions/98966/maximum-theoretical-efficiency-of-internal-combustion-engine

    Any practical process which can significantly improve upon that will do well.

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    Replies
    1. Absolutely. They make no claims for efficiency they get or even the theoretical efficiency they could possibly get. That would help the article immensely.

      My guess is that comparing the efficiency of the Carnot or Otto cycle to a completely different sort of process is probably going to involve some sorts of conversions or (even worse) assumptions by the investigators. I assume they know how.

      One thing for sure, catalysts reduce the activation energy of a reaction and make it "easier". This is all about the new catalyst making hydrogen easier to work with because it's extracted as needed. No high pressure tanks of H2 and no need for a distribution infrastructure that doesn't exist.


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  7. What is needed is a practical gasoline "generator" that uses solar energy to create gasoline molecules from the hydrogen and gasoline in the air. The infrastructure to use gasoline for most of our energy needs already exists. If we combined that infrastructure with placing these "generators" near large population centers it would be even more efficient.


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    1. Aesop:

      The gasoline in the air, Snowflake?

      Where do you live, pray tell, where gasoline molecules float around like unroped steers, just waiting to be rounded up?

      And maybe less "graphic novels", and more textbooks in your reading diet, if you please.

      Just saying.

      If you were referring to magically daisy-chaining oxygen, carbon, and hydrogen atoms into gasoline molecules, alchemists have been trying to do that with matter for 6000 years.

      Take a number.

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    2. Yeah! I was typing too fast and should have said from the hydrogen and carbon in the air. Even so it was obvious to anyone who took High school chemistry what I meant. But I enjoyed the snark never the less.

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  8. Aesop:

    Sounds great.

    Call Popular Science and get it put on the "What's Next?" Futurama crystal ball page (which is the kiss of death for it ever happening, like jet packs and flying cars).

    Meanwhile, call me when they market one for a price anyone still left standing in the middle class can afford.

    And bear well in mind, one or two LZ Hindenburg events (School bus full of kids for $500, Alex)*, and it's over, for evah.



    *(Big Auto, Big Oil, et al would never do something like that, would they? That'd be like buying all the public transport in L.A., and shutting it down to build freeways and force people into cars and suburbs. ;) )

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  9. The occurrence of Platinum on earth is approximately .005 Parts per million.
    The occurrence of Ruthenium on earth is approximately .0001 Parts per million.
    That an enormous difference in availability. The reason Ruthenium isn't that expensive per ounce is because it isn't particularly useful for industry or anything else. If it is needed as a catalyst for energy production that reality changes....dramatically.....as will the price.

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  10. So, is breaking down methane into other substances, then recombining them to make electricity, more efficient than running a generator by combusting the methane in an engine? CH4 + 2xO2 => CO2 + 2xH2O

    Efficiency and simplicity, people. If you have the methane, you already have the power source. And you don't have to deal with China owning most of the rare earth mines.

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